The invention relates to heating and/or air conditioning devices for motor vehicles.
It relates more particularly to a device comprising a cold-air duct, a hot-air duct housing a heating radiator, a mixing chamber communicating with respective air outlets of said ducts, and mixing means suitable for controlling said air outlets in chosen proportions so as to set the temperature of the air in the mixing chamber.
Devices of this type are already known, making it possible to mix a flow of cold air originating from the cold-air duct and a flow of hot air originating from the hot-air duct in controlled proportions in order to obtain an airflow at an adjusted temperature in the mixing chamber.
This airflow is then distributed into the passenger compartment of the vehicle by appropriate distribution means, comprising ducts terminating in various vents arranged at chosen locations in the passenger compartment.
The mixing means generally comprise a mixing flap, of the butterfly type, mounted pivoting about a spindle situated close to the heating radiator and exhibiting two wings suitable for controlling the outlets of the cold-air and hot-air ducts respectively.
Such a flap can be deflected from one to the other of two extreme positions comprising a xe2x80x9chotxe2x80x9d position (in which the outlet of the cold-air duct is closed and the outlet of the hot-air duct is open) and a xe2x80x9ccoldxe2x80x9d position (in which the outlet of the hot-air duct is closed and the outlet of the cold-air duct is open).
Such a device, with a mixing flap of the butterfly type, has the particular drawback that, when the flap passes from the xe2x80x9chotxe2x80x9d position to the xe2x80x9ccoldxe2x80x9d position, cold air enters the mixing chamber from a region of the outlet of the cold-air duct which is located close to a free edge of the butterfly flap. This particular region lies exactly on the opposite side to the region of the outlet of the hot-air duct through which the hot airflow enters the mixing chamber, that is to say close to an opposite edge of the butterfly flap. It results therefrom that the cold airflow and the hot airflow have a tendency to be layered, so that mixing of them can occur only a long way from the heating radiator, which requires an increase in the volume of the mixing chamber and hence of the device.
The object of the invention is essentially to at least partly mitigate such drawbacks.
Hence the invention envisages promoting the meeting and the effective mixing of the cold airflow and of the hot airflow in a region closer to the heating radiator, so as to leave space, downstream of the heating radiator, for the distribution of the air.
According to the present invention there is provided a motor-vehicle heating and/or air conditioning device comprising a cold-air duct, a hot-air duct housing a heating radiator, a mixing chamber communicating with respective air outlets of said ducts, and mixing means suitable for controlling said air outlets in chosen proportions so as to set the temperature of the air in the mixing chamber, wherein the mixing means comprise at least one flap including a shutter wall arranged in such a way that, when they pass from a xe2x80x9chotxe2x80x9d position, in which the outlet of the cold-air duct is closed, to a xe2x80x9ccoldxe2x80x9d position, in which the outlet of the hot-air duct is closed, the shutter wall first of all clears a region of the outlet of the cold-air duct which is close to the outlet of the hot-air duct.
Hence, during the progressive opening of the flap, in order to pass from the xe2x80x9chotxe2x80x9d position to the xe2x80x9ccoldxe2x80x9d position, the flap progressively clears a cold-air passage in a region close to the heating radiator. It results therefrom that the cold airflow and the hot airflow can be mixed optimally and, that being so, the size of the mixing chamber can be reduced by comparison with the known devices.
In a first general embodiment of the invention, the mixing means comprise a main flap mounted pivoting about a spindle and including a wall which, in the xe2x80x9chotxe2x80x9d position, closes the outlet of the cold-air duct and, in the xe2x80x9ccoldxe2x80x9d position is retracted into a position away from the radiator, as well as auxiliary means, coordinated with the main flap, for preventing the hot air passing when the main flap is in xe2x80x9ccoldxe2x80x9d position.
This first general form may be applied to the case in which the heating radiator is suitable for being traversed by a hot liquid under the control of a throughput-setting cock. In this case, the auxiliary means comprise a control suitable for actuating this cock in such a way that it is set in a closed position, preventing the hot liquid from circulating when the main flap is in xe2x80x9ccoldxe2x80x9d position.
This first general form may also be applied to a heating radiator suitable for being traversed continuously by a hot liquid. In this case, the auxiliary means comprise at least one auxiliary flap suitable for closing the hot-air duct when the main flap is in cold position.
This auxiliary flap may be housed in the hot-air duct, upstream of the heating radiator.
By way of example, provision can then be made for the main flap to be a drum flap, and for the auxiliary flap to be a butterfly flap.
It is generally preferred for the auxiliary flap to be suitable for controlling the outlet of the hot-air duct, that is to say for it to be located downstream of the heating radiator.
In such a case, the mixing means essentially comprise a main flap and an auxiliary flap.
The main flap and the auxiliary flap may each be chosen from different types of flaps.
In one embodiment of the invention, the main flap is a drum flap and the auxiliary flap is a drum flap.
Different variant embodiments can then be envisaged.
In one variant, the auxiliary flap is mounted pivoting about a spindle spaced away from the rotational spindle of the main flap.
In another variant, the main flap and the auxiliary flap have respective rotational spindles which are coaxial or substantially coaxial.
Provision can then be made for the main flap and the auxiliary flap to be capable of turning with opposite directions of rotation between the xe2x80x9ccoldxe2x80x9d position in which the two flaps are spaced apart, the main flap opening the outlet of the cold-air duct and the auxiliary flap closing the outlet of the hot-air duct, and the xe2x80x9chotxe2x80x9d position in which the two flaps are brought together and jointly close the outlet of the cold-air duct.
In another variant, the main flap and the auxiliary flap are capable of turning in the same rotational direction between the xe2x80x9ccoldxe2x80x9d position, in which the main flap opens the outlet of the cold-air duct and the auxiliary flap closes the outlet of the hot-air duct, and the xe2x80x9chotxe2x80x9d position in which the main flap closes the outlet of the cold-air duct and the auxiliary flap opens the outlet of the hot-air duct.
In this latter variant, the main flap and the auxiliary flap may form a single-piece assembly and be mounted in rotation about a single spindle.
They can also be separate and mounted in rotation about adjacent parallel spindles.
In another embodiment of the invention, the main flap is a drum flap and the auxiliary flap is a flag flap.
It can then be envisaged, for example, for the main flap and the auxiliary flap to form a single-piece assembly mounted in rotation about a single spindle.
It is also possible for these flaps to be mounted in rotation about parallel respective spindles.
In another embodiment of the invention, the main flap is a drum flap and the auxiliary flap is a butterfly flap. In such a case, the auxiliary flap advantageously includes two non-coplanar wings.
For preference, in this case, the main flap and the auxiliary flap are mounted in rotation in opposite directions about parallel respective spindles.
In another embodiment, the main flap is a flag flap and the auxiliary flap is a drum flap.
Provision can be made for these flaps to form a single-piece assembly mounted in rotation about a single spindle.
It is also possible to provide for these two flaps to be mounted in rotation in the same direction about parallel respective spindles.
In another embodiment, the main flap is a flag flap and the auxiliary flap is a flag flap.
In this case, it is particularly advantageous for the main flap and the auxiliary flap to be mounted in rotation about parallel respective spindles.
In another embodiment, the main flap is a butterfly flap and the auxiliary flap is a drum flap.
In such a case, it is preferred for the main flap and the auxiliary flap to be mounted in rotation in opposite directions about parallel respective spindles.
In another embodiment, the main flap is a butterfly flap and the auxiliary flap is a butterfly flap.
In such a case, it is advantageous for the two flaps to be mounted in rotation in the same direction about parallel respective spindles.